This pair of dongles is a fun way to get your feet wet working with MIDI hardware. They’re called MIDIvampire-I and MIDIvampire-II. Just plug one end into your MIDI-ready instrument and the other into a pair of speakers and you’re off and running. Mark I is a polyphonic synth, and Mark II is a drum machine, but both use basically the same hardware which you may already have on hand.
The single chip on each board is an ATmega328 often found anchoring Arduino boards. The other silicon component is an S1112B30MC voltage regulator. The rest of the components are passives, with MIDI and headphone jacks for connectivity. They’re selling these if you want the easy way out, but we thought we’d bring them to your attention in case you needed a breadboarding project this weekend. The firmware, BOM, schematic, and board artwork are all available on the Wiki pages linked in the articles above. After the break you can see a couple of demo videos which walk through all of the features.